Jun Yokoyama - Academia.edu (original) (raw)

Papers by Jun Yokoyama

Research paper thumbnail of Invasion Status and Potential Ecological Impacts of an Invasive Alien Bumblebee, Bombus terrestris L. (Hymenoptera: Apidae) Naturalized in Southern Hokkaido, Japan

Research paper thumbnail of Deep learning increases the availability of organism photographs taken by citizens in citizen science programs

Scientific Reports, Jan 24, 2022

Research paper thumbnail of New distributional records, taxonomy, morphology, and genetic variations of the endangered brackish-water species Lamprothamnium succinctum (Charales: Charophyceae) in Japan

Journal of Asia-Pacific Biodiversity, 2021

Research paper thumbnail of Expression of the nos gene and firefly flashing: a test of the nitric-oxide-mediated flash control model

Journal of insect science (Online), Jan 19, 2014

Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and popu... more Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and populations of the same species. Their lights are assumed to be biological properties that play important ecological and evolutionary roles. Some species in the Lampyridae emit periodic luminescence, the patterns of which are characterized by species-specific intervals. In previous work, it was predicted that the nitric oxide (NO) regulates the oxygen supply required for the bioluminescence reaction of fireflies. Here, the expression of the NO synthase (NOS) mRNA in some fireflies was examined to verify the predictive model of nitric-oxide-mediated flash control in these insects. The expression of the nos gene in the lantern organ was observed not only in nocturnal flashing species but also in diurnal non-flashing species. It was shown that the expression levels of nos were higher in the lantern of Luciola cruciata (Motschulsky) larvae, which that emits continuous light, than in other body p...

Research paper thumbnail of Genital lock-and-key system and premating isolation by mate preference in carabid beetles (Carabus subgenus Ohomopterus)

Biological Journal of the Linnean Society, 2006

Research paper thumbnail of Wild Crop Relatives: Genomic and Breeding Resources. Temperate Fruits. Edited by C. Kole. Berlin: Springer (2011), pp. 247, £126.00. ISBN 978-3-642-16057-8

Experimental Agriculture, 2011

Research paper thumbnail of Molecular evidences for allopolyploid origins of Plantago asiatica var. densiuscula and P. formosana

Journal of Plant Research, Dec 1, 2006

Research paper thumbnail of A New Peloric Form of Cephalanthera erecta (Orchidaceae) from Japan

Research paper thumbnail of Morphological Variation in the Species of Cephalanthera (Orchidaceae) in Japan

es approximately 16 mixotrophic or holomycotrophic species in Europe, northern Africa, eastern As... more es approximately 16 mixotrophic or holomycotrophic species in Europe, northern Africa, eastern Asia, southeast Asia, and western North America (Luer 1975, Satomi 1982, Chen et al. 2010, Nuraliev et al. 2014). Five species, one variety, and three forms are known to occur in Japan (Yonekura & Kajita 2003 onwards, Yukawa 2015). Additionally, an unknown species of Cephalanthera has been reported from Hokkaido in northern Japan (Yukawa 2009). During our field and herbarium observations, we found variation in species of Cephalanthera that has not been formally recognized. Some of these morphological variants occur by mutation of gene(s) during speciation rather than as transient mutants. Thus, it is important to understand the morphological variations in each species of Cephalanthera. In the present study, we report four examples of morphological variation Cephalanthera.

Research paper thumbnail of Evaluation of the tools for evaluating corporate green spaces and for simplified biodiversity survey

Landscape Ecology and Management, 2014

Research paper thumbnail of Nucleotide Sequence Variations in a Medicinal Relative of Asparagus, <i>Asparagus cochinchinensis</i> (Lour.) Merrill (Asparagaceae)

American Journal of Plant Sciences, 2011

Research paper thumbnail of Selection of Lichens Resistant to the Cosmic Environment<br/>^|^mdash;Thermal Cycle Treatment, UV Irradiation and Heavy Ion Beam Irradiation^|^mdash

Biological Sciences in Space, 2013

Research paper thumbnail of Geographic distribution, host plants, and morphological variation of the currently radiating phytophagous ladybird beetleHenosepilachna diekei

Journal of Natural History, 2015

Research paper thumbnail of The evolution of extreme shell shape variation in the land snail Ainohelix editha : a phylogeny and hybrid zone analysis

Research paper thumbnail of Production and characterization of interspecific hybrids between Asparagus kiusianus Makino and A. officinalis L

Research paper thumbnail of The long-term consequences of hybridization between the two Daphnia species, D. galeata and D. dentifera, in mature habitats

BMC Evolutionary Biology, 2011

BackgroundEcological specializations such as antipredator defense can reinforce morphological and... more BackgroundEcological specializations such as antipredator defense can reinforce morphological and distributional divergence within hybridizing species. Two hybridizing species ofDaphnia(D. galeataandD. dentifera) are distributed in both Japan and North America; however, these populations have a longer history in Japan than in North America due to the differing impact of the last glaciation on these two regions. We tested the hypothesis that this longer coexistence in Japan would lead to extensive genetic admixture in nuclear and mitochondrial DNA whilst the distinct morphological traits and distributional patterns would be maintained.ResultsThe high level of correspondence among morphological traits, distribution, and mitochondrial and nuclear DNA types for the specimens withD. dentiferamtDNA indicated that the species distinction has been maintained. However, a discordance between mtDNA and nuclear ITS-1 types was observed for most specimens that hadD. galeatamtDNA, consistent with...

Research paper thumbnail of Phylogeny of Lespedeza (Leguminosae) based on chloroplast trnL-trnF sequences

aDepartment of Basic Sciences, Faculty of Science and Engineering, IshinomakiSenshu University, 1... more aDepartment of Basic Sciences, Faculty of Science and Engineering, IshinomakiSenshu University, 1, Shinmito, Minamisakai, Ishinomaki, 986-8580 JAPAN; bDepartment of Biology, Faculty of Science, Yamagata University, Yamagata, 990-8560 JAPAN; cFaculty of Agriculture and Agricultural Science Program, Graduate School of Integrated Arts andScience, Kochi University, Nankoku, Kochi, 783-8502 JAPAN; dDepartment of School Education, Joetsu University of Education, Joetsu, Niigata, 943-8512 JAPAN; eBotanical Garden, Tohoku University, Sendai, 980-0862 JAPAN *Corresponding author: tnemoto@isenshu-u.ac.jp

Research paper thumbnail of 詳細な踏査によって明らかとなった伊豆沼の沈水植物の生育状況

Izunuma, Uchinuma kenkyu hokoku, 2013

Research paper thumbnail of 伊豆沼から新たに記録されたアカウキクサ属植物

Izunuma, Uchinuma kenkyu hokoku, 2010

Research paper thumbnail of 伊豆沼・内沼における沈水植物の分布と生育状況

Izunuma, Uchinuma kenkyu hokoku, 2010

Research paper thumbnail of Invasion Status and Potential Ecological Impacts of an Invasive Alien Bumblebee, Bombus terrestris L. (Hymenoptera: Apidae) Naturalized in Southern Hokkaido, Japan

Research paper thumbnail of Deep learning increases the availability of organism photographs taken by citizens in citizen science programs

Scientific Reports, Jan 24, 2022

Research paper thumbnail of New distributional records, taxonomy, morphology, and genetic variations of the endangered brackish-water species Lamprothamnium succinctum (Charales: Charophyceae) in Japan

Journal of Asia-Pacific Biodiversity, 2021

Research paper thumbnail of Expression of the nos gene and firefly flashing: a test of the nitric-oxide-mediated flash control model

Journal of insect science (Online), Jan 19, 2014

Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and popu... more Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and populations of the same species. Their lights are assumed to be biological properties that play important ecological and evolutionary roles. Some species in the Lampyridae emit periodic luminescence, the patterns of which are characterized by species-specific intervals. In previous work, it was predicted that the nitric oxide (NO) regulates the oxygen supply required for the bioluminescence reaction of fireflies. Here, the expression of the NO synthase (NOS) mRNA in some fireflies was examined to verify the predictive model of nitric-oxide-mediated flash control in these insects. The expression of the nos gene in the lantern organ was observed not only in nocturnal flashing species but also in diurnal non-flashing species. It was shown that the expression levels of nos were higher in the lantern of Luciola cruciata (Motschulsky) larvae, which that emits continuous light, than in other body p...

Research paper thumbnail of Genital lock-and-key system and premating isolation by mate preference in carabid beetles (Carabus subgenus Ohomopterus)

Biological Journal of the Linnean Society, 2006

Research paper thumbnail of Wild Crop Relatives: Genomic and Breeding Resources. Temperate Fruits. Edited by C. Kole. Berlin: Springer (2011), pp. 247, £126.00. ISBN 978-3-642-16057-8

Experimental Agriculture, 2011

Research paper thumbnail of Molecular evidences for allopolyploid origins of Plantago asiatica var. densiuscula and P. formosana

Journal of Plant Research, Dec 1, 2006

Research paper thumbnail of A New Peloric Form of Cephalanthera erecta (Orchidaceae) from Japan

Research paper thumbnail of Morphological Variation in the Species of Cephalanthera (Orchidaceae) in Japan

es approximately 16 mixotrophic or holomycotrophic species in Europe, northern Africa, eastern As... more es approximately 16 mixotrophic or holomycotrophic species in Europe, northern Africa, eastern Asia, southeast Asia, and western North America (Luer 1975, Satomi 1982, Chen et al. 2010, Nuraliev et al. 2014). Five species, one variety, and three forms are known to occur in Japan (Yonekura & Kajita 2003 onwards, Yukawa 2015). Additionally, an unknown species of Cephalanthera has been reported from Hokkaido in northern Japan (Yukawa 2009). During our field and herbarium observations, we found variation in species of Cephalanthera that has not been formally recognized. Some of these morphological variants occur by mutation of gene(s) during speciation rather than as transient mutants. Thus, it is important to understand the morphological variations in each species of Cephalanthera. In the present study, we report four examples of morphological variation Cephalanthera.

Research paper thumbnail of Evaluation of the tools for evaluating corporate green spaces and for simplified biodiversity survey

Landscape Ecology and Management, 2014

Research paper thumbnail of Nucleotide Sequence Variations in a Medicinal Relative of Asparagus, <i>Asparagus cochinchinensis</i> (Lour.) Merrill (Asparagaceae)

American Journal of Plant Sciences, 2011

Research paper thumbnail of Selection of Lichens Resistant to the Cosmic Environment<br/>^|^mdash;Thermal Cycle Treatment, UV Irradiation and Heavy Ion Beam Irradiation^|^mdash

Biological Sciences in Space, 2013

Research paper thumbnail of Geographic distribution, host plants, and morphological variation of the currently radiating phytophagous ladybird beetleHenosepilachna diekei

Journal of Natural History, 2015

Research paper thumbnail of The evolution of extreme shell shape variation in the land snail Ainohelix editha : a phylogeny and hybrid zone analysis

Research paper thumbnail of Production and characterization of interspecific hybrids between Asparagus kiusianus Makino and A. officinalis L

Research paper thumbnail of The long-term consequences of hybridization between the two Daphnia species, D. galeata and D. dentifera, in mature habitats

BMC Evolutionary Biology, 2011

BackgroundEcological specializations such as antipredator defense can reinforce morphological and... more BackgroundEcological specializations such as antipredator defense can reinforce morphological and distributional divergence within hybridizing species. Two hybridizing species ofDaphnia(D. galeataandD. dentifera) are distributed in both Japan and North America; however, these populations have a longer history in Japan than in North America due to the differing impact of the last glaciation on these two regions. We tested the hypothesis that this longer coexistence in Japan would lead to extensive genetic admixture in nuclear and mitochondrial DNA whilst the distinct morphological traits and distributional patterns would be maintained.ResultsThe high level of correspondence among morphological traits, distribution, and mitochondrial and nuclear DNA types for the specimens withD. dentiferamtDNA indicated that the species distinction has been maintained. However, a discordance between mtDNA and nuclear ITS-1 types was observed for most specimens that hadD. galeatamtDNA, consistent with...

Research paper thumbnail of Phylogeny of Lespedeza (Leguminosae) based on chloroplast trnL-trnF sequences

aDepartment of Basic Sciences, Faculty of Science and Engineering, IshinomakiSenshu University, 1... more aDepartment of Basic Sciences, Faculty of Science and Engineering, IshinomakiSenshu University, 1, Shinmito, Minamisakai, Ishinomaki, 986-8580 JAPAN; bDepartment of Biology, Faculty of Science, Yamagata University, Yamagata, 990-8560 JAPAN; cFaculty of Agriculture and Agricultural Science Program, Graduate School of Integrated Arts andScience, Kochi University, Nankoku, Kochi, 783-8502 JAPAN; dDepartment of School Education, Joetsu University of Education, Joetsu, Niigata, 943-8512 JAPAN; eBotanical Garden, Tohoku University, Sendai, 980-0862 JAPAN *Corresponding author: tnemoto@isenshu-u.ac.jp

Research paper thumbnail of 詳細な踏査によって明らかとなった伊豆沼の沈水植物の生育状況

Izunuma, Uchinuma kenkyu hokoku, 2013

Research paper thumbnail of 伊豆沼から新たに記録されたアカウキクサ属植物

Izunuma, Uchinuma kenkyu hokoku, 2010

Research paper thumbnail of 伊豆沼・内沼における沈水植物の分布と生育状況

Izunuma, Uchinuma kenkyu hokoku, 2010

Research paper thumbnail of Evaluation of morphological and molecular variation in Plantago asiatica var. densiuscula , with special reference to the systematic treatment of Plantago asiatica var. yakusimensis

Journal of Plant Research, 2006

Morphological and molecular variations in Plantago asiatica L. var. densiuscula Pilg. were analyz... more Morphological and molecular variations in Plantago asiatica L. var. densiuscula Pilg. were analyzed to evaluate the genetic basis for recognizing the dwarf variety P. asiatica var. yakusimensis (Masam.) Ohwi. Considerable variation in the leaf size of P. asiatica var. densiuscula was observed, and no morphological discontinuities were found between the dwarf types of P. asiatica var. densiuscula and P. asiatica var. yakusimensis. Morphological analysis of plants grown under standardized conditions revealed that both environmental plasticity and genetic differentiation contributed to the dwarfisms. Molecular phylogenetic analysis of rDNA internal transcribed spacer (ITS) regions and the SUC1 locus encoding a sucrose transporter revealed that P. asiatica var. yakusimensis was genetically unique although the differentiation level was low. From the above results, we concluded that P. asiatica var. yakusimensis should be reduced to a form of P. asiatica var. densiuscula. Furthermore, the geographic distribution of the SUC1 genotype suggested multiple origins of dwarves, and possible hypotheses for the origins of dwarves are discussed.